The administration by injection of a preparation comprising a pharmaceutical compound is often required to be performed in a relatively short time and with a relatively high local concentration of the pharmaceutical agent. This practice is generally referred to in the field as “bolus” injection. Typically, the term “bolus injection” thus identifies the administration at once (in general within less than few seconds) of a pharmaceutical agent at a high concentration, differently from a gradual administration of the agent (e.g. by means of intravenous infusion).
For instance, in the diagnostic field, liquid preparations of contrast agents (e.g. suspensions of gas-field microvesicles for ultrasound imaging) are often required to be administered as a bolus injection.
Bolus injection is generally achieved by injecting a predetermined volume (the actual bolus) of the desired pharmaceutical liquid preparation followed by a volume of a driving liquid (e.g. saline). According to this technique, it is important, among other things, to precisely determine the volume of the injected bolus and to avoid as much as possible any mixing between the driving liquid and the bolus, as well as any delay between the injection of the bolus volume and the driving liquid.
Several devices and methods have been proposed to collect predetermined volumes of a pharmaceutical preparation and to administer it as a bolus, as disclosed for instance in U.S. Pat. No. 5,053,019.
The Applicant has now devised a new device and system for administering a pharmaceutical preparation as a bolus to a patient.